Chip card with an electronic blocking function

ABSTRACT

The invention relates to a circuit for a chip card, characterized by an active function, which deactivates other function by interrupting the electrical connections. The chip card has two switching elements and two different transmission circuits for exchanging energy and data bi-directionally to an outside location, wherein the transmission circuits are set in a first and a second active function so that when the first active function of the chip card establishes communication, the second active function of the chip card is made inactive.

BACKGROUND OF THE INVENTION

The invention relates to a chip card with a semiconductor chip, in whichfor the energizing of the chip and for the bidirectional datatransmission by means of a terminal from and to the chip, firsttransmission means are provided, such as contacts and/or secondtransmission means, such as contact-free coils and/or capacitors, and/orother energy- and data-transmission means, there being provided on thechip a drivable function element.

With use of chip cards for the bidirectional data transmission it isrequired in many cases always to hold only one transmission path fordata and/or energy in an active function and to cut off the othertransmission paths from their connection to the outside. For example, achip card which is active per contact connection should ensure that thecontact-free connections to the outer world are cut off.

Through DE 39 35 364 as well as U.S. Pat. No. 5,206,495 its U.S.equivalent a chip card has become known which is capable ofautomatically determining its mode of functioning either over contactsor coils. For this the chip card contains a chip (part 2) in which theusual parts of a microcomputer, such as a computing mechanism and astorage element, are accommodated. To the chip there is connected on theone side a contact field with contacts according to ISO standard 7816.On the other side coils are connected to the chip, which serve for thetransmission of energy and the bidirectional data flow. In the chip anelectronic element is present, which makes possible the automaticswitchover from coil function to contact function and conversely, sothat the chip card, either contact-free or contact-encumbered, iscapable of exchanging energy and data with writing/reading terminals.The chip part 2 consists of two essential function elements, namely apart 2.1—which performs in correspondence to the writing/readingterminal which brings about the switchover between contact field andcoils—and a part 2.2 in which the remaining chip functions such ascomputing mechanism and storage response unit are located. In this partthere are carried out those processes which are of importance for theuser of such a chip card, such as debiting of amounts of money, storageof identification numbers, etc. These two parts 2.1 and 2.2 areconnected with each other by means of lines A1, A2, A3 . . . which servein the chip for the part 2.2 as input and output lines for theprocessing of the information in the computing mechanism of that part2.2.

Through EP 534 559 A1 there has been proposed a chip card according toISO standard 7816 and to provisional ISO standard 10536, which,contact-free or contact-encumbered, can exchange energy and data withwriting/reading terminals. The data can be read out according to twodifferent modes, either over long distance by means of low energy—inwhich case only a part of the integrated switching circuit is activated(energy sparing mode)—or there takes place an exchange of energy anddata according to the standardized mode by means of the contacts. Asfurther relevant publications there have become known: DE 43 10 334,PCT/IB 96/00518, DE 195 372, as well as DE 195 31 275.

An analysis of the possibilities of separating chip parts and a solutionof the problems is to be derived from DE 197 52 695 “Electronicswitching element for the blocking of electronic parts in a chip card.”

Through DE-C-44 03 753 a combined chip card has become known whichoperates both contact-free and also contact-encumbered, the IC of whichis embedded into a contact block which presents an additional protectionand can be used as a sensitive switching element for electronicpurposes. In particular, through the function as switching element, theelectronic system can be switched on or off by a card user for purposesof remote transmission. Furthermore, the contact block can be exchanged.

Through DE-A-197 23 272 a chip card with a microcomputer unit has becomeknown, which is connected with electrically conducting contact surfacesfor the contact-encumbered data transfer, and which has a data storagecomponent which is connected with an antenna for contactless datatransfer. A control unit in dependence on a control level establishes aconnection between an antenna and storage element or an antenna andmicrocomputer unit.

SUMMARY OF THE INVENTION

Underlying the invention is the problem of securely carrying out theelectrical separation of connections of the chip card to the outerworld, in dependence on a functional or operating mode of the card.

The chip card of the aforementioned category according to the inventionconsists in that:

1. the function element in dependence on a first or second function oron a first or second working mode of the semiconductor chip drives oneof two switching elements (S1 or S2),

2. wherein the first function or working mode of the semiconductor chipis characterized by an energy and/or data exchange over the firsttransmission means,

3. wherein the second function or working mode is characterized by anenergy and/or data exchange over the second transmission means,

4. wherein the first function is active, as it cuts off parts of, or theentire electrical connection of the data and/or energy exchange tomaintain the second function of the card over the further transmissionmeans, with the exception of the active function, and conversely.

According to the invention it is a matter of a chip card with a chip inwhich different drivable components, such as microprocessors and storageelements are contained. The most diverse means can serve for theenergizing, and for bidirectional data transmission from and to thechip. There are possible and known contacts, as well as means for thecontactless data transmission, in the form of coils or capacitors. Therecan also be provided other energy and data transmission means and/ormeans such as are present as electronic, miniaturized elements for thereception of sound or pressure or for the capacitive reception ofelectric signals in fingerprint sensors. On the chip there is provided adrivable function element which recognizes the particular functionalstate or mode, whether the chip card is to operate contact-encumbered orcontactless. This function element can be a comparison member, forexample a comparator or operation amplifier, according to the part 2.1.2of DE-C-39 35 364.

The function element, in dependence on this first or second function oroperating mode of the chip, triggers one of the switching elements S1 orS2. With the elements S1, S2 it is a matter of electronic parts orswitching circuits which are suited for cutting off electric lineconnections, insofar as they have a voltage lying on their controlinput. The first function/mode of the semiconductor chip ischaracterized by an energy exchange and/or data exchange with theoutside of the card (with parts that are not contained in the chip, suchas, for example terminals) over the first means. The first means arethose that mark the active state of the card. In a card this can be theconnection over the contacts or over the coils. The second function/modeis characterized by an energy and/or data exchange over further means.If the first function is active, then parts of, or the entire electricalconnection of the data and/or energy exchange should be cut off from thefurther or other functions of the card with the exception of the activefunction. The particular active function should cut off the possibleother functions from any data exchange.

The function mode is to be described in the example of a chip card thatcontains both contacts and also coils for the energy and/or dataexchange with the environment, as with a terminal. If data come in overthe contacts, these data are worked up for further use in a part, as anentry port for transport over lines. The data arriving from the coilsare worked up by a further part, as entry port, for transport overfurther lines. If now the function element perceives the activation ofthe chip card over the contacts or the coil, as, for example, the originof the voltage, for example according to DE-C-39 35 364, then one of theswitching elements S1 and S2 can be activated and the connection tooutside the card can be cut off. In such manner, for example, themodulated-on signals that arrive over the coils, can be cut off beforetheir demodulation, for the purpose of data recovery from the entryport, part 2.1.4.

It can happen that certain functions are activated within the same briefspans of time. In each case the dominant function which arises first intime over the time span, should block the others over the switchingelements S1, S2.

In all cases in which other functions are already active, the functionshould serve the switching elements S1 or S2 over dominant contacts.Therewith a clear priority is to be established between the differentpossible active states.

If a card is activated over contacts or if it is activated duringanother function over contacts, the contacts represent the strongestenergy supply (power supply). Also, the reference potential (VCC of thecontacts) is stable with respect, for example, to contact-free referencepotential, since it is connected with the potential in a terminal. Ifline connections or signal outputs or data lines from or to the furtherfunction parts are laid on the voltage base potential of the contactinput, it is ensured that no other signal—namely no other data, signals,logical levels or energies—remain stable; they will adapt themselves tothe reference potential. In this manner there is determined anelectrical dominance of the contact function.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a circuit diagram for an embodiment of an execution of theinvention, and

FIG. 2 is a further circuit diagram for the realization of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A chip card according to FIG. 1 contains a contact field with contacts 3of a contact connection, and coils 4, 5 or capacitors or othertransmission elements of a contact-free connection for thecontact-encumbered or contact-free exchange of data and/or energybetween a chip card 1 and a writing/reading terminal (not shown). Thechip(s) present in the chip card can be connected to the contacts 3, aswell as to the coils 4, 5 and/or to capacitors and/or other transmissionelements of a contact-free connection. According to the surroundingfield of the chip card, i.e., according to the writing/reading terminalin which the chip card is located, energy and data are exchanged on thebasis of the working mode determined by a function element 2.1.6 overcontacts 3 or coils 4, 5 and/or capacitors and/or other transmissionelements of a contact-free connection with the writing/reading terminal.The function element 2.1.6 corresponds to the part 2.1.2 in DE-C-39 35364 incorporated herein by reference and acts with its output on acircuit 2.1.3 (FIG. 2), which can be a throw switch or a multiplexer.The outputs A1 . . . An of the circuit 2.1.3 make available an energysupply to further chip parts or to a farther chip or to several chips ina part 2.2 (FIG. 2), in which there are located the remaining chipfunctions, such as computing mechanism and storage units; the chip cardin this manner fulfills its intended function, for example incontact-encumbered and/or in contactless mode of operation.

When data come in over the contacts 3, these are worked up for furtheruse in a part 2.1.5 for transport over lines I1-I6. The data and/orenergy coming in from the coils 4, 5 are worked up by a part 2.1.4 fortransport over lines. K1 . . . K5. The parts 2.1.4 as well as 2.1.5have, for example, entry ports or entry latches or entry gates for thesuppression of voltage peaks or for the signal preparation.

In the contact connection of the lines I1 . . . I6 of the contacts 3there lies a switching element S₁ for the cutting-off of the contactconnection or of the lines I1 . . . I6, respectively, just as in thecontact-free connection of the lines K1 . . . K5 of the coils 4, 5and/or of the capacitors and/or of other transmission elements therelies a switching element S2 for the cutting-off of the contact-freeconnection or of the lines K1 . . . K5. If the function element part2.1.6 recognizes the activation of the chip card either over thecontacts 3 or over the coils 4, 5, as, for example, the voltage isrecognized, for example according to DE-C-39 35 364, then either theswitching element S1 or the switching element S2 can be activated, andthe connection of the chip card to the outside, that follows it, can becut off.

FIG. 2 shows a circuit diagram similar to FIG. 1. In a general manner,in a contact connection I1 . . . I6 of contacts 3 to a switching circuit2.1.3, which according to DE-C-39 35 364 can be a throw switch or amultiplexer, there lies an electrical or electronic switching elementS1. Likewise, in a contact connection K2 . . . K5 of coils 4, 5 and/orcapacitors and/or other transmission elements to the switching circuit2.1.3 there lies a switching element S2, in which arrangement the twoswitching elements S1, S2 which are represented symbolically asswitches, cut off the corresponding contact connection on theirrespective triggering through the switching circuit 2.1.6. When functionelement 2.1.6 receives the report, over a connection or coupling E2, ofthe activation of the contact-encumbered connecting contact I1 . . . I6then the switching element S2 is activated through the function element2.1.6, and the contact connections K1 . . . K5 of coils 4, 5 and/orcapacitors and/or other transmission elements to the switching circuit2.1.3 are interrupted. Then no simultaneous manipulations can be carriedout over the coils 4, 5 while the contacts are activated.

If, conversely, the function element 2.1.6 receives the report, over E1,of the activation of the contactless contact connections K1 . . . K5then the switching element S1 is activated by the function element2.1.6, and the contact connection I1 . . . I6 is cut off, so that overthe contacts 3 no simultaneous manipulations can be carried out over thecontacts 3, therefore while the coils 4, 5 are activated.

The invention is usable industrially to improve the security againstmanipulations, of chip cards which are capable of operating bothcontact-encumbered and also contact-free. The usefulness of theinvention lies especially in that in this manner, however, furtherfunctions of the chip card in contrast are deactivated, as electricalconnections are cut-off by an active function or by an active workingmode of the chip card.

As is apparent from the foregoing specification, the invention issusceptible of being embodied with various alterations and modificationswhich may differ particularly from those that have been described in thepreceding specification and description. It should be understood that Iwish to embody within the scope of the patent warranted hereon all suchmodifications as reasonably and properly come within the scope of mycontribution to the art.

What is claimed is:
 1. A chip card with at least one semiconductor chip,wherein different transmission means are provided on the chip card for asupply of energy to the chip from an outside location and forbi-directional data transmission from and to the chip from the outsidelocation, and on the chip there is also arranged a triggerable functionelement which is arranged to perceive an energy and/or data exchangebetween the chip card and the outside location over the differenttransmission means as a first and a second active function, the chipcard further comprising two switching elements arranged such that whenan electrical voltage is applied to them, are capable of cutting offelectric line connections, wherein after perception by the triggerablefunction element of the first active function brought about by theenergy and/or data exchange with one of the transmission means, thetriggerable function element triggers one of the two switching elements,which one switching element blocks the energy and/or data exchange withthe other transmission means, or after perception by the triggerablefunction element of the second active function, brought about by theenergy and/or data exchange with one of the other transmission means,the function element triggers the other switching element, which otherswitching element blocks the energy and/or data exchange with the othertransmission means, so that through a particular active function of thetriggerable function element brought about by the energy and/or dataexchange with one of the transmission means, the energy and/or dataexchange with the other transmission means, with exception of one of theactive functions, is blocked, in which case a function occurring firstin time dominantly blocks the other active function over an allocatedswitching element and, any actuation of the chip card over contacts,line connections or signal outputs or data lines from and/or to furtherfunction parts of the chip card are laid on a voltage ground potentialof a contact input, so that electrical dominance of a contact functionis determined.
 2. The chip card according to claim 1, wherein a functionover contacts in all cases dominantly serves a connected one of theswitching elements.
 3. The chip card according to claim 1, whereinwithin a contact connection to a switching circuit, a first electronicswitch element is provided, and within a connection of contract-freetransmission elements to this switching circuit, there is arranged asecond electronic switching element, wherein, in an activation of thecontact connection, the function element activates the second electronicswitching element, which blocks the contactfree connection, andconversely in the activation of the coils and/or capacitors and/or othertransmission elements.
 4. A chip card with at least one semiconductorchip comprising: a first transmission means on the chip card for asupply of energy to the chip from an outside location, and a second,different transmission means on the chip card for bi-directional datatransmission from and to the chip from the outside location, atriggerable function element arranged on the chip to perceive an energyand data exchange between the chip card and the outside location overthe different transmission means as a first and a second activefunction, the chip card further comprising two switching elementsarranged such that when an electrical voltage is applied to the twoswitching elements, they are capable of cutting off electric lineconnections, wherein the triggerable function element is arranged suchthat after perception by the triggerable function element of the firstactive function brought about by the energy and/or data exchange withone of the transmission means, the triggerable function element triggersone of the two switching elements, which switching element is arrangedto block the energy and/or data exchange with the other transmissionmeans, or after perception by the triggerable function element of thesecond active function, brought about by the energy and/or data exchangewith one of the other transmission means, the triggerable functionelement is arranged to trigger the other switching element, and theother switching element is arranged to block the energy and/or dataexchange with the other transmission means, so that through a particularactive function of the triggerable function element brought about by theenergy and/or data exchange with one of the transmission means, theenergy and/or data exchange with the other transmission means, withexception of one of the active functions, is blocked, in which case afunction occurring first in time dominantly blocks the other functionover an allocated switching element and, any actuation of the chip cardover contacts, line connections or signal outputs or data lines fromand/or to further function parts of the chip card are laid on a voltageground potential of a contact input, so that an electrical dominance ofa contact function is determined.
 5. The chip card according to claim 4,arranged such that a function over contacts in all cases dominantlyserves a connected one of the switching elements.
 6. The chip cardaccording to claim 4, arranged such that within a contact connection toa switching circuit, a first electronic switch element is provided, andwithin a connection of contract-free transmission elements to thisswitching circuit, there is arranged a second electronic switchingelement, wherein, in an activation of the contact connection, thefunction element activates the second electronic switching element,which blocks the contactfree connection, and conversely in theactivation of the coils and/or capacitors and/or other transmissionelements.